1. Field of the Invention
The invention relates in general to a backlight module and a display device using the same, and more particularly to a backlight module with a light guiding member and a display device using the same.
2. Description of the Related Art
Along with the development in display technology, a flat display has been widely used in a variety of electronic devices as result of the features of lightweight, slimness and compactness. In general, the flat display includes a display panel and a backlight module. The backlight module includes a light source, a light guide plate and a plurality of optical films. The light generated by the light source is guided to the optical film through the light guide plate, so that the light is provided for the display panel disposed on the backlight module. In the disposition of the light source and the light guide plate, if the light generated by the light source cannot be precisely emitted into the light guide plate, dimmed part may occur to the frame generated by the display panel.
In general, when the light source of the backlight module is realized by a lamp tube, the tube-type backlight module further includes a mask. Since the mask is correspondingly fixed the light guide plate and the light source, and the mask is fixed on an iron member of the display, the occurrence that the light cannot be emitted into the light guide plate can be reduced. In comparison, when the light source of the backlight module is realized by a light emitting diode (LED), the light source and the light guide plate cannot be fixed through the mask due to the structural difference. Once the light guide plate is moved (due to warpage for example), a part of the light cannot be emitted into the light guide plate, so that the luminance is decreased.
For example, during the manufacturing process of the light guide plate, the light guide plate is baked after the printing process. However, during the baking process, the edge of the light guide plate may be warped, so that the light emitting surface of the LED cannot be precisely aligned with the light incident surface of the light guide plate. Thus, the light generated by the LED cannot be precisely emitted into the light guide plate. Moreover, due to the assembly tolerance, temperature change or humidity change, the light generated by the LED cannot be precisely aligned with the light guide plate, so that the projection path of the light generated by the LED biased. Therefore, how to provide a backlight module capable of precisely projecting the LED light into the light guide plate has become a prominent task for the industries.